Stents are generally cylindrically shaped devices configured to hold open and/or expand a segment of a blood vessel or other body lumen. For example, a stent may be used to maintain the patency of a body lumen, such as a blood vessel, subsequent to a percutaneous transluminal angioplasty (PTA) or percutaneous transluminal coronary angioplasty (PTCA) procedure, or other procedure used to open an obstructed body lumen.
One type of stent, known as self-expanding stents, are configured to be delivered in an elastically compressed state while being confined within a tubular restraining member, and then allowed to elastically expand into engagement with the interior of the body lumen when removed from the tubular restraining member.
One embodiment of a catheter delivery system is the so-called “over-the-wire” delivery system, in which a catheter is introduced into the patient over a guide wire which has been previously introduced. In this embodiment, the guidewire extends through the entire length of the catheter through a lumen of the catheter. Another embodiment of a catheter delivery system is the so-called “rapid-exchange” delivery system, in which the guidewire extends through only a distal portion of the catheter from the distal tip to a guidewire port located proximal of the distal tip.
Prior art “over-the-wire” stent delivery systems for delivering self-expanding stents may be undesirable as such systems lack the capability to be rapidly advanced over a guidewire and/or exchanged for another delivery system during a medical procedure in a rapid-exchange manner. Furthermore, such over-the-wire systems require the use of a longer wire for exchanges than a rapid exchange system. Some such systems are disclosed in U.S. Pat. Nos. 6,019,778; 5,702,418; 5,026,377; and 4,580,568, the disclosures of which are incorporated herein by reference.
Prior art “rapid-exchange” stent delivery systems for delivering self-expanding stents require the stent to be pre-loaded in the delivery catheter distal of the guidewire port prior to being inserted into the body of the patient such that the guidewire extends through the stent or a separate lumen of the catheter, thus reducing the flexibility and/or maneuverability of the distal portion of the delivery catheter. Some such systems is are disclosed in U.S. Pat. Nos. 7,527,643; 7,468,053 and 5,690,644 and U.S. Pat. Pub. Nos. 2005/0113902, 2009/0105808, and 2010/0125322, the disclosures of which are incorporated herein by reference.
There is a need to provide a stent delivery system for delivering a self-expanding stent to a target location utilizing a delivery catheter having rapid-exchange capabilities for gaining access to a target location yet providing empty lumen capabilities for delivering a stent to the target location through the lumen of the delivery catheter.